diff --git a/nbviewer/providers/github/handlers.py b/nbviewer/providers/github/handlers.py
index 879a5be5..cf34ebf3 100644
--- a/nbviewer/providers/github/handlers.py
+++ b/nbviewer/providers/github/handlers.py
@@ -198,7 +198,7 @@ def render_treelist_template(
             **namespace,
         )
 
-    async def _internal_get(self, user: str, repo: str, path: str, ref: str) -> str:
+    async def _internal_get(self, user: str, repo: str, ref: str, path: str) -> str:
         """
         Hook into here later during testing – probably via a CLI.
         Do avoid doing actual github requests.